Generally, in an Internet broadcasting, a main server, which provides Internet broadcasting data, transmits multimedia data to all terminals connected to the server itself. Many Internet users receive the broadcasting data, such as moving pictures and audio data, etc., by connecting to the Internet broadcasting server That is, according to the current Internet broadcasting system, all of users may connect to the main server regardless of the number of users.
With speedy multimedia technology development, an amount of transmitting data increases, thereby happening a bottleneck problem and down of the server.
Especially, in case of the Internet broadcasting, an increasing of data capacity is necessary because quality of video and audio data affects competitiveness. To provide good quality of Internet broadcasting in the above-mentioned situation, efficiency and capacity of server should be increased.
Even though the server has good efficiency and large capacity, when many users are connected to the server, other users who want to connect to the server may not connect to the server. Even if a user may connect to the server, data transmission rate slow down, so that the good quality of broadcasting cannot be provided.
Also, if the above-mentioned situation happens repeatedly, or many users of which number is larger than a threshold value are tried to connect to the server at the same time, the server is downed and the Internet broadcasting may not be provided until the server is repaired.
Generally, in an Internet, data transmission is carried out by using a transmission control protocol/Internet protocol (TCP/IP) or a user datagram protocol (UDP).
To perform an Internet broadcasting by using the TCP/IP or the UDP, the same data have to be transmitted to the terminal as many times as the number of the terminals.
An IP multicasting is used to solve the above-mentioned problem. An IP multicasting is an Internet standard, which is made for broadcasting multimedia data such as moving picture data and audio data, and thereby establishing a special Internet address domain, so called “class D”. Also, among the address of the domains, if a terminal receives data, then the data is transmitted to all terminals having the same address.
However, if an Internet router to which a terminal is connected does not support the IP multicasting, it only can be used in a local area network (LAN) to which the terminal is connected. Particularly, the server and the terminal in an Internet have to pass multiple Internet routers to connect each other, so among the routers, if one router doesn't support the IP multicasting, the terminal can not receive the broadcasting data from the server.
Moreover, the IP multicasting supporting routers are not provided sufficiently, the Internet broadcasting using the IP multicasting is practically impossible. With this reason, the Internet broadcasting which uses the IP multicasting is rate until now, and it is currently used in only an intranet system within an enterprise.
Currently, most Internet broadcasting servers use the TCP/IP or the UDP instead of the IP multicasting to thereby receive broadcasting data by directly connecting to a server and a terminal.
The above-mentioned Internet broadcasting method gives large communication load to the server and has difficulty in the number of the users connected to the server cannot be increased. Also, an access denial by the overload of the server, a data lost, a decreasing of communication speed and a down of a server may be brought about, thereby utilizing an expensive server equipment having a high capacity.